Bit-brace chuck.



B. A. SGHADE.

BIT BRAGE GHUGK.

APPLICATION FILED MAY 24, 1910 967,837. Patented Aug. 16, 1910.

THE NORRIS P ETER5 (30-, WASHINGTQN. U. C

I IE g UNITED STATES PATENT OFFICE.

EDMUND A. SCI-IADE, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE STANLEYRULE & LEVEL COMPANY, OF NEW BRITAIN, CONNECTICUT, A CORPORATION OFCONNECTICUT.

BIT-BRACE CHUCK.

Specification of Letters Patent.

Patented Aug. 16, 1910.

Application filed May 24, 1910. Serial N 0. 563,127.

To all whom it may concern:

Be it known that I, EDMUND A. SCHADE, a citizen of the United States,residing at New Britain, county of Hartford, State of Connecticut, haveinvented certain new and useful Improvements in Bit-Brace Chucks, ofwhich the following is a full, clear, and

t exact description.

This invention relates to improvements in chucks of a type particularlyuseful in connection with bit braces.

The object of the invention is to provide a simple and effective meansto secure uniform action of the jaw members.

In the drawings: Figure l is a side elevation partly in section of a jawsuch as employed in connection with bit braces, a portion of the bracebeing shown; Fig. 2 is a section taken on a plane at right angles to theplane of the parts as shown in Fig. 1 and showing the jaws expanded andapplied to a round drill shank; Fig. 3 is a similar view showing theparts applied to a round drill shank of smaller size; Fig. 45 is asimilar view but somewhat more in section and showing the parts appliedto the angular head of an ordinary bit; Fig. 5 is a detail view partlyin section; Fig. 6 is illustrative of another detail detached; Fig. 7illustrates different views of still another detail.

1 is the main body of the chuck which I will term the driver.

2 is the jaw controlling shell which is screw-threaded on to the body ofthe driver 1. The body of the driver 1 is longitudinally slitted fromits forward end to receive the jaws 33 such as customarily employed. 4is an abutment block also located in said slot and having two recedinginclines at its forward end, against which the rear ends of the jaws 33bear and ride. The outer end of the shell 2 has a tapered annular wallfor engaging the outer ends of the jaws 33 whereby when the shell isscrewed back on the body 1, the jaws 33 are contracted or ressed towardeach other, said jaws riding I own the two receding inclines at theoppoite ends thereof.

In chucks of this type much difficulty is xperienced in securingparallel action of e jaw members. Various means have been evised toaccomplish this end, but the folwing simple means I have found to beexedingly eflective. The opposite sides and e rear of the block 4 aregrooved and recessed to provide a space for receiving a U-shaped springcarrier 5, said spring carrier being properly fitted to the space in therear of the abutment block 4:, so that it may move to and fro to alimited extent but will not tilt. 66 are springs carried by the carrier5 and connected at their forward ends to the jaws 33 respectively. Asthe jaws are moved to and fro, they will operate in substantialparallelism, so that a round drill shank may be readily inserted. InFig. 2, I have shown in place a round shank 7 of a drill of large size.In Fig. 3, I have shown the chuck as gripping the round shank 8 of asmall drill. While this con struction tends to normally preserveparallelism of the jaws, they can nevertheless be tilted, by reason ofthe yielding action of the spring members 66 so as to assume theposition indicated in Fig. 4t, wherein said jaws are shown as grippingthe usual tapered conical shank 9 of the ordinary boring bit. Thecarrier 5 partakes of suflicient sliding movement to and fro relativelyto the axis of the chuck and within the recess at the rear of the block4 to permit the rear ends of the jaw members to ride up and down 011 thetwo inclines at the front end of said block 4, but, since said carrier 5cannot tilt out of line with the axis of the chuck, it follows that onejaw cannot be projected or retracted at any time more than its companionjaw, but the degree of projection of said jaws will at all timescorrespond.

It should be stated that the normal action of the spring connectionbetween each jaw and the carrier is to expand or move apart the jaws, sothat they will follow the inclines at the ends thereof, riding outwardlythereon as the jaw operating shell is screwed outwardly on the driver.

It will be understood that I have shown and described only the preferredform of my invention.

What I claim is:

1. In a chuck, in combination, a driver having a longitudinal slottherein, a pair of jaws standing in said slot, an abutment block in saidslot at the rear ends of said jaws, said abutment block having oppositereceding inclines at its forward end and grooves in its opposite sides,a jaw-operating shell surrounding said driver having a tapered orinclined outlet for engaging the outer ends of said jaws, a U-shapedspring carrier guided on 'said block and in said grooves and arranged tomove to and fro in 2. In a chuck, in combination, a driver havingalongitudinal slot therein, a pair of jaws standing in said slot, anabutment block in said slot at the rear ends of said jaws,'said abutmentblock having opposite receding inclines at its forward end, a jawoperating shell surrounding said driver having a 'tap'ered or inclinedoutlet for engaging the outer ends of said jaws, said abutment havingguide grooves in its opposite sidesand a recess in its rear connectingsaid grooves, a reciprocating U-shaped spring carrier guided on saidblock and standing in said grooves and capable of limited longitudinalmovement, and a spring connection between each jaw and said carrier.

3. In a chuck, in combination, a driver having a longitudinal slottherein, a pair of jaws standing in said slot, an abutment block at therear end of said slot, said abutment block having opposite recedinginclines at its forward end against which said jaws bear, ajaw-operating shell surround.- ing said driver and having a tapered orinclined outlet for engaging the outer ends of said jaws, jaw expandingsprings rigidly secured to said jaws respectively, means to permit saidsprings to move longitudinally relatively to the abutment block and tohold said springs against unequal movement.

EDMUND A. SGHADE. Witnesses W. J. WORAM, I. W. CHAPMAN.

